This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. Food allergy is becoming a major health problem in the United States, affecting about 2.5% of the population, or 6.5 million Americans. Peanut and tree nut allergies affect about 1.1% of the population1 and fish and shellfish affect approximately 0.5% - 0.7%. Other foods, such as kiwi and various seeds [e.g. sesame, mustard, poppy, etc.] appear to be an increasing problem. Although milk, eggs and peanuts account for over 80% of food hypersensitivity reactions in children,2 hypersensitivity reactions to peanuts, tree nuts, seeds and seafood tend to be more severe in nature, sometimes resulting in death,3;4 and generally are lifelong.5 Despite the prevalence of these food hypersensitivities and the number of serious anaphylactic reactions each year, the identification of clinically relevant allergens is incomplete and our understanding of the immunobiology of peanut, tree nut, seed and seafood hypersensitivity is very limited.6-9 The overall goal of this project is to characterize food allergens responsible for clinical reactivity to a variety of foods and to isolate DNA encoding these proteins. A bank of food allergen DNA will enable us to take advantage of any of a number of novel strategies under investigation for modulating the allergic response in food allergic patients